1. Field of the Invention
The present invention relates in general to a liquid crystal display (LCD) panel. In particular, the present invention relates to thin film transistors (TFTs), color filters, black matrixes disposed on the same substrate of the LCD panel.
2. Description of the Related Art
LCDs have the advantages of low power consumption, thin profiles, light weight and low driving-voltage. LCDs have been put to practical use with personal computers, navigation systems, hand held gaming devices, projectors, view finders and portable electronics (watches, electronic calculators and televisions).
In a conventional thin film transistor liquid crystal display (TFT-LCD) panel, the backlight module results in high power consumption. Varied TFT structures and manufacturing approaches such as increasing the backlight power or increasing the transparency of the LCD have been disclosed, to reduce power consumption.
FIG. 1 is a cross sectional diagram showing a conventional LCD panel structure. The conventional LCD panel 10 includes: two glass substrates (bottom substrate 101 and top substrate 110), a black matrix 109, a color filter 112, a passivation layer 107, a transparent conductive layer 106 such as indium tin oxide (ITO), a plurality of TFTs (herein, only one TFT is shown) 105, and a liquid crystal layer 111. The glass substrates 101 and 110 are oppositely disposed each other. The black matrix 109 is disposed on the top substrate 110, and the color filter 112 is disposed on the top substrate 110 and the black matrix 109. The passivation layer 107 and the transparent conductive layer 106 are sequentially disposed on the color filter 112. TFTs 105 are disposed and arranged on the bottom substrate 101 to create TFT array. The liquid crystal layer 111 in which liquid crystal has been filled is formed between bottom substrate 101 and top substrate 110.
In FIG. 1, the TFT 105 used for LCD panel 10 is directly formed on the bottom substrate 101 near the backlight module (not shown), and the color filter 112 is formed on the top substrate 110. Since TFT array is directly formed on the bottom substrate 101 near the backlight module, the transparency of the LCD panel 10 is decreased. This results in poor picture quality.
In addition, each TFT 105 in the TFT array has a bottom gate structure (as shown in FIG. 1), and fabrication of the conventional LCD panel 10 requires at least five patterning masks. This results in higher manufacturing cost. Furthermore, it is difficult to achieve mass production.
Therefore, increasing the picture quality and simplifying the TFT process steps is a very important issue for the LCD industry.